NEMA and UL Standards Comparison by Type of Electrical Enclosures
The National Electrical Manufacturers Association (NEMA) and Underwriters Laboratories, Inc. (UL) are ratings organizations for commercial electrical devices and their applications. Their respective ratings are based on manufacturers’ documented expectations of performance, specified by type, but they differ in standards compliance requirements. NEMA allows compliance to standards as determined by the manufacturer. UL requires a third-party evaluator to determine manufacturer compliance to standards.
The following comparisons for indoor and/or outdoor enclosures are organized by enclosure type and rating organization. NEMA employs Standard 250. UL employs Standards UL50 and UL508.
Type 1
- NEMA
Indoor use provides a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt. - UL
Indoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt.
Type 1 Screw Cover
Type 2
- NEMA
Indoor use provides a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt, as well as protection from damaging effects of invasive liquid materials such as dripping or splashing water. - UL
Indoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials.
Type 3
- NEMA
Indoor and outdoor use provides a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt and wind-driven dust. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, or hail. The external enclosure will be protected from damage by ice formation. - UL
Indoor and outdoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials. The external enclosure will be protected from damage by ice formation.
Type 3R
- NEMA
Indoor and outdoor enclosures are protected against personal contact with dangerous components. It also protects internal components from external materials such as dirt and wind-driven dust. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, or hail. The external enclosure will not be damaged by ice formation on the enclosure. - UL
Indoor and outdoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials. The external enclosure will be protected from damage by ice formation.
Type 3R Hinged Cover UL Listed
Type 3S
- NEMA
Indoor and outdoor enclosures are protected against personal contact with dangerous components. It also protects internal components from external materials such as dirt and wind-driven dust. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, or hail. The external enclosure will not be damaged by ice formation on the enclosure. External components will still function when encased by ice. - UL
Indoor and outdoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials. The external enclosure will be protected from damage by ice formation. External components will remain functional when encased by ice.
Type 3X
- NEMA
Indoor and outdoor enclosures are protected against personal contact with dangerous components. It also protects internal components from external materials such as dirt and wind-driven dust. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, or hail. The external enclosure will not be damaged by ice formation on the enclosure. The enclosure will prevent corrosion and damage caused by external formation of ice. - UL
No standard applies
Type 3RX
- NEMA
Indoor and outdoor enclosures are protected against personal contact with dangerous components. It also protects internal components from external materials such as dirt. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, or hail. The external enclosure will not be damaged by ice formation on the enclosure and will provide additional measures to prevent corrosion and damage caused by external formation of ice. - UL
No standard applies
Type 3SX
- NEMA
Indoor and outdoor enclosures are protected against personal contact with dangerous components. It also protects internal components from external materials such as dirt and wind-driven dust. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, or hail. The external enclosure will not be damaged by ice formation on the enclosure. The enclosure will prevent corrosion and damage caused by external formation of ice. External components will still function when encased by ice. - UL
No standard applies
Type 4
- NEMA
Indoor and outdoor enclosures are protected against personal contact with dangerous components. It also protects internal components from external materials such as dirt and wind-driven dust. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, hail or water from a hose. The external enclosure will not be damaged by ice formation on the enclosure. - UL
Indoor and outdoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials such as rain, snow, hail or water from a hose. The external enclosure will be protected from damage by ice formation.
Type 4X
- NEMA
Indoor and outdoor enclosures are protected against personal contact with dangerous components. It also protects internal components from external materials such as dirt and wind-driven dust. It also protects internal components against damaging effects of invasive materials such as dripping or splashing water or rain, snow, hail or water from a hose. The external enclosure will not be damaged by ice formation on the enclosure. External components will still function when encased by ice. - UL
Indoor and outdoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials such as rain, snow, hail or water from a hose. The external enclosure will be protected from damage by ice formation. External components will remain functional when encased by ice.
Type 4X Hinged Cover Junction Box
Type 5
- NEMA
Indoor and outdoor use provides a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt, collected airborne dust, fibers and lint. It will protect from damaging effects of invasive materials such as dripping or splashing water. - UL
Indoor and outdoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt, collected airborne dust, fibers and lint. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials.
Type 6
- NEMA
Indoor use provides a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt. It provides protection from damaging effects of invasive materials such as dripping or splashing water, water from a hose, or infrequent, temporary submersion in water at a limited depth. The external enclosure will not be damaged by ice formation on the enclosure. - UL
Indoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials, water from a hose, or infrequent, temporary submersion in water at a limited depth. The external enclosure will not be damaged by ice formation on the enclosure.
Type 6P
- NEMA
Indoor use provides a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt. It provides protection from damaging effects of invasive materials such as dripping or splashing water, water from a hose, or infrequent, temporary submersion in water at a limited depth. The enclosure will prevent corrosion and damage caused by external formation of ice. - UL
Indoor use offers protection against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt. It also protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials, water from a hose, or infrequent, temporary submersion in water at a limited depth. The external enclosure will not be damaged by ice formation on the enclosure.
Type 7
- NEMA
The enclosure design will contain an internal explosion without generating an external hazardous incident. - UL
Indoor use in classified hazardous locations defined as Class 1, Division 1, or Groups A, B, C, or D in accordance with NFPA 70 (National Fire Protection Association).
Type 8
- NEMA
The enclosure design will prevent combustion when using oil-immersed components. - UL
Indoor and outdoor use in classified hazardous locations defined as Class 1, Division 1, or Groups A, B, C, or D in accordance with NFPA 70.
Type 9
- NEMA
The enclosure design will prevent combustible dust ignition. - UL
Indoor and outdoor use in classified hazardous locations defined as Class 1, Division 1, or Groups A, B, C, or D in accordance with NFPA 70.
Type 10
- NEMA
The enclosure design will not cause an external hazard while containing an internal explosion. - UL
The enclosure will meet the standard of the Mine Safety and Health Administration, 30 CFR, Part 18.
Type 12
- NEMA
The enclosure will be designed without knockouts for indoor use to provide a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt, collected airborne dust, fibers and lint. It will protect from damaging effects of invasive materials such as dripping or splashing water. - UL
The enclosure will be designed without knockouts for indoor use to protect against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt, collected airborne dust, fibers and lint. It protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials. It also protects against incidental splashing and resulting seeping of oil and non-corrosive coolant materials.
Type 12 Screw Cover
Type 12K
- NEMA
The enclosure will be designed with knockouts for indoor use to provide a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt, collected airborne dust, fibers and lint. It will protect from damaging effects of invasive materials such as dripping or splashing water. - UL
The enclosure will be designed with knockouts for indoor use to protect against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt, collected airborne dust, fibers and lint. It protects internal components from damage by invasion by external sources of dripping or incidental splashing of non-corrosive liquid materials. It also protects against incidental splashing and resulting seeping of oil and non-corrosive coolant materials.
Type 13
- NEMA
Indoor enclosure use to provide a protected measure to prevent personal contact with dangerous components. It also protects internal components from external materials such as dirt, collected airborne dust, fibers and lint. It will protect from damaging effects of invasive materials such as dripping or splashing water. It will also protect against incidental splashing and resulting seeping of oil and non-corrosive coolant materials. - UL
Enclosure for indoor use to protect against personal contact with internal components and a measure to protect internal components from access by external materials such as dirt, collected airborne dust, fibers and lint. It protects internal components from damage by invasion of dripping or incidental splashing of non-corrosive liquid materials, and seeping of water, oil and non-corrosive coolant materials.
FAQs
What is the difference between NEMA and UL enclosure ratings? ›
Both define enclosure designs, what contaminants each design can provide protection for, and how each design is tested to assure compliance with its respective rating or type. The most significant difference between NEMA rated enclosures and a UL type rated is how testing is done and the compliance process.
What is NEMA 4 vs UL? ›The protection Type 4 enclosures afford slightly ramps up things further, however the main difference between UL and NEMA definitions is just the common language used. Unlike NEMA, UL requires manufacturers to perform independent checks, and the same applies to type 4 enclosures.
What is a UL type rating? ›IP and UL Type 50 (NEMA) enclosure ratings determine how well the enclosures of electronic components resist the infiltration of dust and moisture.
What are NEMA standards and NEMA ratings? ›NEMA ratings are standards that are useful in defining the types of environments in which an electrical enclosure can be used. The NEMA rating system is defined by the National Electrical Manufacturers Association, and frequently signifies a fixed enclosure's ability to withstand certain environmental conditions.
Is NEMA the same as UL? ›NEMA allows compliance to standards as determined by the manufacturer. UL requires a third-party evaluator to determine manufacturer compliance to standards.
What does UL mean in HVAC? ›Luckily, UL (Underwriters Laboratories) approved products make that decision simpler, ensuring required standards are met such as safety, sustainability, performance, and quality. In addition, UL certified products must pass testing that is set forth by UL and the IEC (International Electrotechnical Commission).
What does NEMA 4 rating mean? ›Type 4: Weather tight (weatherproof) enclosures. Constructed for either indoor or outdoor use to provide a degree of protection against falling dirt, rain, sleet, snow, windblown dust, splashing water, and hose-directed water. Will be undamaged by the external formation of ice on the enclosure.
What is NEMA 4 vs 4X rating? ›What is the difference between NEMA4 and NEMA4X? NEMA 4 is a rating that indicates the HMI, when properly mounted in a panel, can provide protection against dirt, rain, and windblown dust, including hose directed water. NEMA 4X is the same as NEMA 4 but must also provide protection against corrosion.
Is Type 4 the same as NEMA 4? ›Both ratings indicate a waterproof and dust-tight enclosure that provides excellent protection against airborne particulates, adverse weather conditions, and repeated hose-downs. However, a NEMA 4X enclosure has an additional feature that a NEMA 4 enclosure lacks: protection from corrosion.
What is a NEMA rated enclosure? ›NEMA ratings are a convenient system established by the National Electrical Manufacturers Association to rate how well various types of electrical enclosures protect against environmental hazards such as dust and dirt, water ingress (whether hose-directed, precipitation or submersion) and corrosion.
What is the difference between UL and NEC? ›
The NEC establishes listing requirements, and UL meets those requirements in what it certifies (bearing in mind that the term “Listed” as used in the NEC is not the same as “UL Listed”).
What does UL stand for in NEC? ›In the electrical world, UL stands for Underwriters Laboratories, an independent testing company that provides third party product safety standards and certification.
What does NEMA enclosure stand for? ›NEMA Enclosure Ratings
The National Electrical Manufacturer Association (NEMA) uses a standard rating system that defines the types of environments in which an electrical enclosure can be used, and frequently signifies a fixed enclosure's ability to withstand certain environmental conditions.